Duplex screw driver



Dec. 18, 1928.

P. E. BORKLUND DUPLEX scnw DRIVER Filed Jan. 1e. 192e ZEBoril/zuc? Ll l) ative bit.

Patented Ecc. 1S, 1928.

= iiifii'isn STATES tennis .PATENT oFFicjE,

PETER E. RoRRLUNn'oF sPoRANR, WASHINGTON.

DUPLEX soREw DRIVER.

Application inea January 16, 192s. serial No. aimez.

yThe object of this invention is to provide an improved screw gripping screw driver. A further object isto provide a duplex screw driver adapted for use on screws ofV a lwide range of size. j

A further. feature consists in a novel yform of sleeve for `the bar on which the screw vdriver bits are formed,said sleeve. having on kopposite ends Vthereof sets of g A further object is to provide means for structurally and frictionally locking the sleeve andy bar to the shank in' the various adjusted positions so that thek tool will be free from slop. j

My invention also resides in the sleeve, as a new and useful article of manufacture. The invention has many other features and objects that will be more fully described in connection with the accompanying drawing and which will be more particulary pointed out in and by the appended claims. ln the drawing; y Fig. 1, is 'a plan view of the preferred form of` the invention showing the screw holdingl fingers in retracted vrelation with their res ective bit.

Fig'Q, is a view in side elevation with the parts in the same adjustment.

Fig, 3, is a view of a portion ofthe tool Vshown in Fig. 1, in plan, with the fingers adjusted into coactive relation with the oper- Fig. 4, is a side view thereof, parts in the same adjustment asr shown in Fig. 5, is a sectional view'on line 5-5o-f iig. '2, showingthe parts on an enlarged scale. Y j, Fig. 6, is a sectional view on line 6 6 of Fig. 5, looking toward theleft thereof.'k

Fig. 7, is a View. in side elevation of the uros of the drawing.

which will presently appear.

lwith .theL

shank with the bit bar and sleeve being partially adjusted to bring one of the ends into an operative position. 1

j Fig. 8, isa developed plan View ofl the blank from which the sleeve is formed,

showing the same on av small scale. f Fig. 9, is an end view of the screw holding fingers.

b Fig. 10, `is a side elvation of the bit ar. v

I Like characters of reference designate similar parts throughout the different fig- As sli-own, a handle is indicated at 1, the

. same-having a thiinble 2, preferably of metal and the end 3, of which is adapted to form a shoulder stop. Attached to and projecting from said thimble 2, is a 'shank A, which,

in thev present construction, isV bifurcated rfioml a bight 5, outwardly, the limbs being indicated. at 6. VIn cross section, the shank 4l is circular, and as will be seen in Fig. 5,

Ithe limbs 6, are Vgenerally cylindrical eX- ceptfor the interruption caused'by the bifurcation thereof. The inner faces 7, of said limbs 6, are preferably flat and from a point 8, inwardly to bight 5,.said linibs are slightly cut-away, as indicated at 9, for apurpose I will next describemy improved bit bar which is more particularly shown'in Fig. 10, on ra reduced scale. i

Said bar is designated at` 10 andin side elevation, it is of the contour shown, the

5. The ends of said bar 10, as indicated at same being showniii cross section in Fig.

11', are reduced fromthe greatest width as lshown at 12, and said-ends are shaped to yform screwdriver bits 13 and 14, the former beingl for are'latively large range or size of screws and the latter for the smaller sizes,

Mid-way'between theends thereof, said bar u .said bitvv bar.

There vis shown a bit bar enclosing or enfveloping sleeve having identical' side vwalls 16, anedge wall 17 and a split edge wall composed of videntical flanges 18, 'all as shown more clearly in Fig. 5. As shown in Fig. 1, the edge Vwalls terminate at-9 and Y 20- from which points, outwardly,flie sleeve is forked to format each end of the sleeve,

"Figs, 1 and Q,

`limbs 6, the sleeve is 'li a set of screw holding lingers. Adjacent the larger bit 13, the fingers are indicated at 21,

and the ends 22 thereof are bent inwardly from point 20, to form wardly bent ends Q5, iden In the Valls 16, of said sleeve, l provide slots 26 for a purpose which l am now about to describe. l

Reference will next be made to the manner and means for mounting the bit bar and "its sleeve onto the shank.

ln cases wher-e the shank is a forked shank, as shown, l employ means such as a pivot27, extending through limbs 6, and through slots 26 and through opening 15, 'the heads of the aivot being suitably set in rigid relation tothe limbs, which heads are shown at 28. rlllhus, the har l0, with its slidable sleeve, is pivotally mounted' in the shank so that the vbar 10 can be turned end for end to dispose either bitlf-B or let in en operative position with respect vto the shank. The elongated slots 26, afford movement for the sleeve such as will dispose the lingers in the desired position with respect to the bits. Movement of `the sleeve, longitudinally of the bit bar 10, is effected by manually grasping the sie .ve with the hand, ln order to .prevent binding, and afford free; longitudinal shifting movement of the sleeve on the bit bar 10, l provide means which is preferaby in the form of spacing washers 29, which are preferably sLuare, and which are disposed over the ,pivot 27between the bar 10 and the limbs 6 and within the slots 26. These washers 29, are slightly thicker than the walls 1G, of the sleeve, so tliat when the heads 28 are riveted or swaged in place,

1, in an adjustment that will illustrate the reason for slightly recessing the walls 9, sol

that the latter will `accommodate the fingers when the latter are inV a normal position and not under tension.

l will rnez-.zt describe the means forl holding` the bit bar 1.0, and its sleeve in rigid relaillustrated in Fie.y

limbs .against the sleeve.

tion to the shank and in a manner to pre- V` vent LslopLW j A ferrule 30, is slidably mounted on the holding shank in a manner to be adjusted from the full to the dotted line positions shown in'Figs. 1V and 2. Said ferrule slides easily on the shank from shoulder 3, to a Vpoint near the end 8 of the reduction of walls 9, and from that point, the diversion of the limbs 6, ail'ords friction to the ferrule 30, and to slide the same any further, tends to bend the limbs 6, between the pivot 2?, and the bight 5, and thereby compress said As' an alternative of the foregoing, or supplemental thereof, and preferablythe latter, l proportionthe sleeve in such a manner or o`n such dimensions that they edge walls thereof project Y slightly above aline marking the total dianr eter of the limbs and near the endsV o'f the sleeve, I reduce the saine as shown at 31, as regards the left hand end in Figs. 2, and il, and at 32, Vas regards the right 'hand end, as shown in `Fig. 2. Thus, when the ferrule 30 is shifted far enough :to ride up on the central extended portion ofthe sleevev and over the reduced portions 31y or 32, the ferrule will not only structurally lockthe bar 10, in its adjusted position, but it willso rigidly and frictionally secure the sleeve that both the bar and sleeve will be held iirmly in position against slop. This is4 an important feature in an .adjustable screw driver, as a wobblya action lwould render the driver very ineicient, especially .10o

an adjus'tabledriver.

I consider vit a novel feature to make a sleeve, as shown and described, Vfrom a blank as illustrated in Fig. 8, on a reduced scale. ASaid blank is made with the stock' los constitute the remaining set of v'llhese projections are formed in a manner to ,aan

leave enough stock for one complete edge wall, asshown at 35, and to leave edge por-- tions 36, for the walls 18. The slots Q6, are.. formed in the blank as shown atB?. Thus when the blank is v:folded on a general medial. line Aa`bout the bar 10, or about any suit' able former, and the portions 36 are bent in. place, the sleeve will be complete asshown.

Vlhile the device of inventionmay be clear as regards operation, from the fore'- going description, it may be briefly recapitm ulated as follows:y Y j f In the adjustments shown in Figs. land 9J, the bit 13, can be used inthe usual capacity, for a screw driver. a screw, either a wood or a machine screw, in a place that is inaccessible to the hands, then, the ferrule 30 is `shifted back to the dotted line position thereby leaving .the

sleeve free to be manually adjusted so that iso If it is desired to start ist.'

lingers will bein a screw holding position, as shown in Figs. 3 and 4." When the ferrule is again,l advan-ced toV the locking positionyas shown' in full lines, the screwl will be firmly held and can be started. After the screw has been started,-the ferrulev can be shifted back to the dotted linepositionV to free the sleeve for retraction ofthe latter to the Figure l, position. Then, the-ferrule can be again advanced to lock the, bar 10 and sleeve in a fixed position against slop It will be seen that the coaction betweenV the ferrule SO and the reduced portions 3l and 32 of the sleeve is of a very flexible nature that compensates for a wide variety of adjustments of the sleeve with respect to the bit bar 10. For instance, when the sleeve is in the retracted adjustment shown in F ig. 1, the reduced portions 32 would be nearer the bight 5, than when the sleeve was forced outwardly into the Fig. 3 adjustment, and yet, the ferrule is movable to whatever position is necessary `in order to effect Aengagement with the sleeve and frictionally lock and hold the latter vand its.

fork such limitations as the claims may t. to pivotally mount the latter, and a locking import.

I claim: e y

l. In a duplex screw driver, a bit bar havinga bit on each end thereof, a sleeve encasing said bar and having a set of screwholding fingers on each end thereof and being slidable on said bar to dispose either rset of l fingers incoacting or retracted relation with the respective bit thereof, a forked holding shank, meansv pivotingsaid'bar in the fork of said shank for end for end adjustment of said bar with respect to said shank to dispose either bit in projecting relation from said shank, and a ferrule slidable on said shank for locking said bar in its adjusted position.

2. In a duplex screw driver, a bit bar having a bit on each end thereof, a sleeve enclosing' said bar and edge portions of said sleeve being cut away and the resultant free ends being bent inwardly to forma set of screw holding fingers on each end of said sleeve and said sleeve being slidable longitudinally along said bar to disposeeither set of iingers in coacting or retracted relation with respect to its respective bit, and a handle shank in which said parts are mounted. j

3. In a duplex screw driver, a bit ybar havling a bit on each end thereof, a sleeve enclosing said bar andhaving a set of resilient screw holding fingers on each end thereof and said sleeve beingslidablei on said bar to dispose eitherfset oirfingers in coacting or retracted relation with respect to the adjacent bit, said sleeve-having pivot slots in opposite walls thereof, a forked holding shank, a pivot extending through .the fork ends of said `shank and through said slots and through an intermediate portion of said bar to pivotally mount the latter in said shank, spacing washers disposed on said pivot and located in said slots betweeny said forked ends and said bar and being of a thickness to slightly space said forkedends Lin working clearance relation to said sleeve to permit free movement of the latter, and

a locking ferrule slidable on said shank tov ward said pivot to enclose and lock said vsleeve and bar and compress the intermediate forked portions of said shank against said sleeve to rigidly hold said bar in its` adjusted position against slop 4. YIn a duplex screw driver, a bit bar havt ing a bit on each end thereof, a sleeve enclosing said bar and having'a set of screw holding fingers oneach end thereof and said sleeve being` slidable on said bar to dispose either set of fingers in coacting or retracted relationrwith respect to the adjacent bit, a forked shank having its limbs reduced from its bighttowardits ends to render said limbs i inwardly vbendable, a pivot extending through the forked ends of said shank and through an intermediate portion of said bar ferrule slidable on said shank toward said pivot to enclose and structurally lock said sleeve and bar and compress intermediate portions of said limbs against said sleeve ksaid bar having a set of screw holding fingers on eachy end thereof and being' slidable'on said bar to dispose eitherv set of fingers in coacting or retractedL relation'to the respective and nearest bit, a holding shank pivotally united with said bar for end forv end adjustment of said bar, and means forlocking or holding said bar in its adjusted position with respect tosaid shank. v

6. In` aduplex screw holding` screw driver, a forked. shank, a bit 'bar' having a bit on each Vend thereof and pivoted between its ends in the forked ends of said shank, a sleeve on said bar'having a set of screw holding lingers, one set for each bit, and said sleeve being slidably adjustable on said bar to dispose a set of fingers in coactive` or,

yretracted relation to the active bit, anda Said baiq in position by engaging said sleeve irrespective of the longitudinal position of seid sleeve on said bai'.

7. In a duplex screw holding screw driver, a shank forked to form limbs, a bit bai' having@ bit at each end thereof, a sleeve 1ongitudinally slidabie on said bai* and having sets of screw holding fingers at each end thereof and the Walls of said sleeve being slotted, a pivot extending through the ends of said 4:limbs and through the slots of said Sleeve and through seid bai', spacing .Washers on stud pivot between said limbsrand bit bar for spacing the ends of said limbs in elearanceV relation to seid sleeve to slightly di- Verge said limbs, and a `fief-rule movable on seid limbs to contract the latter against and iDETER n. BonKLUNn. 

